PSLE
The pie charts show the number of each type of stationery in 2 stationery boxes, M and N. The total number of stationery in Box M is twice the total number of stationery in Box N.

1. Find the percentage of post-it pads in Box M.
2. What fraction of stationery in Box N is post-it pads?
3. The number of post-it pads in Box M is 280. Find the number of post-it pads in Box N.

(a)
^90°_360° = 25% of stationery in Box M

Percentage of foolscaps in Box M = 25%

Percentage of post-it pads in Box M
= 100% - 40% - 25%
= 35%

(b)
Percentage of post-it pads in Box N
= 100% - 50% - 20%
= 30%

Fraction of stationery in Box N that is post-it pads
= ³₁₀

(c)
35% of stationery in Box M = 280
1% of stationery in Box M = 280 ÷ 35 = 8 
100% of the stationery in Box M = 100 x 8 = 800

Number of stationery in Box N
= 800 ÷ 2
= 400

100% of stationery in Box N = 400
1% of stationery in Box M = 400 ÷ 100 = 4
30% of stationery in Box M = 30 x 4 = 120  

Number of post-it pads in Box N = 120

Answer(s): (a) 35%; (b) ³₁₀; (c) 120